package it.benjamin.aspirinweb.mem;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
/**
* 获取Springboot上下文，通过上下文可以拿到配置文件中的配置参数
*/
@Component
public class AppContextTool implements ApplicationContextAware {
private static ApplicationContext context;
public String getConfig(String key) {
return context.getEnvironment().getProperty(key);
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.context = applicationContext;
}
}
定义一个AppUtil.java类：
public class AppUtil {
public static ConfigurableApplicationContext CONTEXT;
}
在启动类中进行赋值
public static void main(String[] args) {
AppUtil.CONTEXT = SpringApplication.run(RedisFlinkApplication.class, args);
}
实现ApplicationContextAware，重写setApplicationContext方法。这个方式下，工具类也被注册成了Bean，既然这样，那就必须确保该类能被Spring自动扫描到。
@Component
public class SpringContextUtils implements ApplicationContextAware {
private static ApplicationContext applicationContext;
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
SpringContextUtils.applicationContext = applicationContext;
}
public static <T> T getBean(Class<T> cls) {
if (applicationContext == null) {
throw new RuntimeException("applicationContext注入失败");
}
return applicationContext.getBean(cls);
}
public static Object getBean(String name) {
if (applicationContext == null) {
throw new RuntimeException("applicationContext注入失败");
}
return applicationContext.getBean(name);
}
public static <T> T getBean(String name, Class<T> cls) {
if (applicationContext == null) {
throw new RuntimeException("applicationContext注入失败");
}
return applicationContext.getBean(name, cls);
}
public static HttpServletRequest getRequest() {
ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder
.getRequestAttributes();
return requestAttributes == null ? null : requestAttributes.getRequest();
}
}
我想要的工具类，往往会部署在公共jar中，一般情况下不能被SpringBoot程序扫描到。所有就有手动注入上下文的方式。
@Slf4j
public class SpringUtils {
private SpringUtils() {
}
private static ApplicationContext context = null;
/**
* 初始化Spring上下文
*
* @param ctx 上下文对象
*/
public static void initContext(ApplicationContext ctx) {
if(ctx == null) {
log.warn("ApplicationContext is null.");
return;
}
context = ctx;
}
/**
* 根据类型获取Bean
*
* @param cls Bean类
* @param <T> Bean类型
* @return Bean对象
*/
public static <T> T getBean(Class<T> cls) {
return context == null ? null : context.getBean(cls);
}
/**
* 根据名称获取Bean
*
* @param name Bean名称
* @return Bean对象
*/
public static Object getBean(String name) {
return context == null ? null : context.getBean(name);
}
/**
* 根据Bean名称和类获取Bean对象
*
* @param name Bean名称
* @param cls Bean类
* @param <T> Bean类型
* @return Bean对象
*/
public static <T> T getBean(String name, Class<T> cls) {
return context == null ? null : context.getBean(name, cls);
}
}
此种方式不用实现ApplicationContextAware接口，但是需要手动设置上下文。所以在程序入口处，需要调用initContext方法，完成上下文的初始化。
public static void main(String[] args) {
ApplicationContext context = SpringApplication.run(YCloudsServiceBApplication.class, args);
SpringUtils.initContext(context);
}
GitHub地址：https://github.com/ye17186/spring-boot-learn
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
